Epoxy resins have been precatalyzed with phosphonium and other compounds to provide latent compositions which form advanced, higher molecular weight epoxy resins when admixed with an aromatic hydroxyl-containing compound as disclosed by Perry in U.S. Pat. No. 3,948,855 and Can. 893,191; by Dante et al. in U.S. Pat. No. 3,477,990; by Mueller et al. in U.S. Pat. No. 3,547,881; by Tyler, Jr. et al. in U.S. Pat. No. 4,366,295; and by Cragar in Can. 858,648.
While compositions containing these catalysts and an epoxy resin are somewhat stable, such compositions which also contain an aromatic hydroxyl-containing compound are lacking in stability.
Curable compositions containing epoxy resins and aromatic hydroxyl-containing compounds and a catalyst therefor would be highly desirable in the preparation of storage stable coatings, storage stable electrical encapsulants, storage stable formulations for preparing mechanical and electrical laminates and composites, storage stable one package molding compositions, storage stable curable compositions for use in resin transfer molding (RTM) and reaction injection molding (RIM) applications and the like.